DD152422A1 - METHOD AND MEASURING DEVICE FOR DETERMINING THE HEAT INJECTION MATERIAL AND THE HEAT INJECTION RESISTANCE - Google Patents

Abstract

The aim and object of the invention is to provide a simple, non-destructive working measuring method that allows the determination of the mean Waermeeindringfaehigkeit multi-layer plate-like body, the Waermeeindringfaehigkeit a not readily accessible by a cover layer flat bottom layer and the Waermeeindringwiderstandes any Fußbodenkonstruktiunen without much time and equipment , According to the invention, the test specimen is brought into contact with a flat heating surface fixed to the measuring device, and the contact temperature registered by means of thermocouples is evaluated.

Description

a) Title of the invention

Method and instrument for determining the permeability of oil or the penetration of oil

b) Field of application of the invention

The invention relates to a method including the associated measuring device for non-destructive determination of the heat-penetrating capacities of two-layered platy-shaped bodies as well as the mean heat-permeability or heat-penetrating resistance for a specific period of time and multilayer plates for laboratory investigations as well as for measurements on objects in use, such as ZeB * for the control of foot heat "" Derivation of multi-layer floor construction in construction ".

2 22 88 8

c) Characteristic of the known technical solutions

The measurement of the heat-penetrating capacity b of a substance is based on the short-term method according to KRISCHER and ESDORN, described in VDI «Vol. 450, 1954, back. * A flat, constant-power heating surface is placed between two plate-shaped bodies of the test specimen and the heating process registered in the contact surface. Due to the setup of the experiment, the method remains limited to the laboratory "Examinations · The value of a building part in use, for example, is not possible« Moreover, the determination of the heat-penetrating properties of multi-layered bodies is not possible « * and communal hygiene foot heat dissipation of foot floor constructions exist a number of so-called "artificial feet", the structure and operation of SCHÖLE already in "Reports from Building Research" Issue 40, Berlin 1964 has been comprehensively presented. A solid or water container heated to a constant temperature is placed on the ground and the heat flow is measured in the contact surface. · A measurement of the average heat infiltration capacity or heat penetration resistance, which determines the foot heat dissipation, ζ.Β · according to TGL 35424/07 computational proof is not possible ·

d) Object of the invention

The object of the invention is to develop a nondestructive measuring method including the required measuring devices, which allows not only homogeneous body but also to detect the frequently encountered in practice stratified material arrangements with respect to their Wärmeeindringwerte metrologically and directly prescribed for Fußwärmeableitung parameter measurable close.

e) Presentation of the essence of the invention

The technical problem which is solved by the invention is that "at preferably two-layer, plate-shaped Körpern.die Wärmeeindringfähigkeiten b ₁ and bp and two" and multi-layer boards, the heat penetration coefficient b • medium or "the middle liVärmeeindringwiderstand R _£ for a period t to be determined non-destructively on test specimens and in use condition.

According to the invention the object is achieved by a cuboid measuring body, on its underside a flat heating foil, which may be of a be «. heatable guard ring is surrounded, and a thermopile are attached, with the surface of the specimen kor «clocked«. Here, the timing of the contact "temperature ^{^>} i ^<(t) or the contact temperature will be at a certain time ^ VCT ₀₎ - ^ ^{ei unr to} ^ ^e i ^{r> e} '~ constant heat output registers"

If a constant heat flow density q flows one-dimensionally into a two-layer test specimen with the heat-penetrating properties b (cover layer) and bp (lower layer), the following relationship arises for the heating process in the heating surface

(W

/ V A J. -ρ / O ₁ 1 J

if only s.

Thickness of the top layer thickness of the bottom layer temperature of the material and the measuring body before heating

Thermal conductivity of the cover

2 22896

The time derivative of (1) is

2Σ

(1-1-

chi

.2

For times t ^ 1, the second summand remains in the

^a i

Bracket small against i and it applies

dt (2)

(3)

H dfT (4)

It follows

d-ΓΤ (5)

For times t

(eg · t> 4 | i for <^ <4) ^D 2

goes over (2) into

dt (6)

dl t

2q

DFT "

can be determined «

ζ ζ ζ by 6

If one applies (1) over f ~ F, the increase at the beginning of the measurement gives the value b. and at the end of the measurement the value bp of the not directly accessible lower layer »

Analogously, it can be shown that when using the time derivative for measuring value the influence of the heat transfer resistance between the measuring body and the test object falls out after a short measuring time, and therefore generally no 'strictly reproducible coupling of the measuring device to the test object is required.'

The average heat penetration coefficient b or _e, the average Wärmeeindringwiderstand R _£ for the period t of a more "* fling s 'hich-term Che * s can be made of a temperature value υ i>(t') be determined.

For (1) can be written *

r _e «« ^ ^. (10)

It is approximately

^S 1 ^b 1 ^S 1 2

R. --A- (I - -i) for t>. (- A -.) ^ (12)

^E ^ l ^b 2 T?

and in a nano-layered test piece

^b n ^b n

^s i

2 2 289 6 -.6 -

b or * Rg are used, for example, as parameters for describing the foot heat dissipation of a »and multi-layered floor constructions and thus according to the invention directly accessible to a metrological control»

f) embodiment.

Figure 1 shows the construction of a measuring device with the measuring body-1 · It consists of PUR foam with a in the contact surface measuring body / specimen mounted meandering 5 .5 xi m thick heating foil 2 of constants / which is surrounded by a separately heatable guard ring 3, and a thermopile 4, the Ver¬ equalization 5 housed in an unheated location of the contact surface or »outside the measuring body is installed» The constant heating power from 1 to IO W is supplied to the heating foil from the outside by a DC voltage regulator or via a battery The protection ring performance is so choose that for the entire time frame of the measurement the power density. , q flows one-dimensionally into the test specimen 6 * The thermoelectric voltage and thus the excess temperature ^ P _K (t) ^ P is used for the mood of the patient . medium oil permeability b externally indicated by a standard DC voltmeter or registered for the determination of the individual values b ,,, b ₂ . If the heat "eindringfahigkeit of Meßkörpermaterials known ^ the unit works as Absolutmessero The method is suitable, inter alia for controlling the Wärmeeindringwiderstandes R _£ a" and multi-layer floor constructions in construction. In accordance with the contact side foot / floor of t = 5 min on which this is based, the heat flux q remains one dimensional even without guard ring 3 for dimensions of the heating foil 2 of A> 0.15 × Ojl5 m

Claims (1)

Erfindunasanspruch Procedure for nondestructive determination of heat penetration capacity or heat penetration resistance is characterized by a constant one - dimensional heat flow q into the material to be measured over a flat heating surface surrounded by a separately heatable guard ring for times t> 0 the temperature ^ J ^{1 is} fed in and the temporal temperature profile in the contact area is evaluated © Method according to item 1 », characterized in that in the case of two-layer plate-shaped bodies of the heat-penetrating capacities b ₁ and b" the temperature increase d ^ P. at the beginning of the measurement © in direct measure for b * df ~ F and at the end of the measurement for b "· Method according to item I ₉ characterized by the fact that in multi-layered plate-shaped bodies (z "B" in a floor construction) the temperature increase in the contact surface after time t a direct measure of the average permeability b or of the heat penetration resistance R _£ is · Measuring device for non-destructive determination of the Wärrneein "" dringfähigkeit or · the Wärmeeindringwiderstandes _e ge "is characterized in that an insulating material cuboid having an opening formed as a meander or spiral heating surface of a metallic alloy, which is optionally surrounded by a se" ready heatable guard ring of the same material "and a Thermopile is brought into contact with the test specimen, and about a temperature measurement zer «· 222896 - se trouble-free determination of heat penetration capabilities b. and bp is possible with a two-layer panel and the average heat penetration capacities b or of the heat penetration resistance R _£ for a period t for a panel having any desired number of parallel layers of fabric and thus the characteristic value for the foot heat dissipation of a floor construction. For this 1 page drawing